Automatic vehicle temperature control



June 29, 1965 D. E. JOHNSON ErAL 3,191,669

AUTOMATIC VEHICLE TEMPERATURE CONTROL Filed May 2l, 1962 2 Sheets-Sheet 1 if 41 L f7 June 29, 1965 D. E. JoHNsoN 4l-:TAL 3,191,669

AUTOMATIC VEHICLE TEMPERATURE CONTROL 2 Sheets-Sheet 2 Filed May 2l, 1962 NQA lwlli Mimi. I lww|-| Ziff? United States Patent() 3 191 669 AUTOMATIC VEHICL TMPERATURE .CONTROL Dale E. Johnson, 1619 6th St.; Allen E. Hert, 1001R St.; and Hubert H. Sakel, R.R.V 3, Box 274, all of Bedford,

Filed May 21, 1962, Ser. No. 196,179 Claims. (Cl. 165-25) This invention relates generally to temperature control systems and more particularly to temperature control systems for automotive vehicles. l

In recent years, motor vehicle manufacturers have marketed vehicles and particularly automobileswhich have means intended for establishing a desired passenger compartment temperature regardless` of ther outside ambient temperature. In order to do so the vehicles have been equipped with heating units as well as cooling units. Normally the heating unitemploys engine coolant which is circulated by the engine water Vpump and air flow is provided principally by an electric motor driven fan. The cooling unit incorporates refrigeration mechanisms including a compressor which is normally driven by the engine. Again, air flow is provided by an electric motor driven fan. l 1 j `Heretofore, in vehicles which have not incorporated a cooling system, but in which the heat output of the heater Was'to be controlled according to the passenger compartment temperature, the -usual means of controlling the heat output has been to employ a thermostatically con'- `trolled valve in the water line from the engine to the heat Yexchanger core of the heater. .'fan has been controlled manually. Also, for effective Operation of the heater operation of a defroster supplied withy warm'airfrom the heater core, it is necessary to adjust the temperature control to be certain lthat maximum water ow through the heater core is provided, and also to adjust a damper `control to direct the entire air iiow output from the heater to the defroster duct. This has not only required the attention to control of two separate knobs, but alsohas caused `an attendant time lag of substantial duration .until adequate water ilow is established. Of. course,

another two manual Voperations are required when the cdefrosting operation is 'completed and return to auto- `matic temperatureV control is desired.4

' In vehicles equipped with `air conditioning as well as heating units, it has been the typical practice to provide a master control whereby either the heating system is deactivated and the cooling system activated or vice versa depending on the outside ambient condition.` With such systems, in addition to the usual complexity which they the cloud cover conditions make it impossible for either the .air-conditioner alone or the heater alone to maintain a satisfactory vehicle temperature. For example, if the `desired temperature in the passenger compartment is 75 F., and the outside ambient temperature is 50 F., heater l operation is required to bring the passenger compartment temperature up to the desired level, so long as the sun is not shining. However, if the clouds `are, scattered, it is involve, there is a problem which is encountered on the .Y l

type of day where the ambient temperature together with 3,191,669 j Patented June 29., 1965 provided without any automatic Atemperature control equipment. `This means that the person whobuys a vehicle which has heating equipment but with no automatic control, has been for-ced to operate with such equipment for the entire life or at least his period of use of the vehicle.

It is therefore a general object of the present invention to provide improved means for automatic temperature controlof a vehicle. y AIt is a further object ofthisinvention to provide an extremely simpleand trouble-free means forV automatic `control of temperature in a vehicle equipped with a heater. j

It is a Afurther object of thepresent invention toprovidemeans for easily equipping a standard vehiclewhich has `a straight manual control of its heating unit with an automatic Vcontrol at nominal expense. j

It is a further object of the present invention to provide means for' automatically maintaining temperature in the passenger compartment of a vehicle at a stable point regardless of ambient temperature conditions.

It is a further object of the present invention to provide `means for .maintaining a speciiied temperature ina vehiclev equipped f with air ,heating and cooling equipc ICS ment and requiring absolutely no attention to the tem- Described briey, a typical embodiment of the present Vinvention is incorporated in an engine-driven motor vehicle having a liquid cooled engine, heater and. air cooler,

`with separate defroster and compartment heating outlets and a damper for, excluding air from the heating outlet when desired. In the typical embodiment, a control unit fis provided whichi'includes a case which maybe conveniently mounted to the vehicle body in the passenger compartment, usually behind or underthe instrument panel.' The control unit includes a snap-action switch having normally-open and normally-closed contactsfj An Y adjustable thermally-responsive element is provided for operation of the switch in response to passenger compartment temperatures. The case is suitably perforated to encourage air ilow therethrough.

A manually operable lever is mounted in the case and has connected thereto a .Bowden wire which isV coupled to the damper in the "heater duct. The manual lever is also operatively associated with the switch whereby it can actuate the switch independently of the thermally responsive unit upon placing the manual lever in a predeterminedV position thereof. At this `position the lever also locates theA damper whereby it excludes air iiow from the passenger compartment heating outlets and directs all of` theheater air output to the defroster outlets.

Air supply to the heater is provided by an electrically driven heater fan and the normally-open contacts `of the micro-switch areconnected in circuit with the heater fan motor and the vehicle battery. Thereby the heater fan motor is de-energizedwhenever the normally-open contacts are open and is energized whenever they are closed either by the action of the manual lever or by the response of the thermally responsive element to a passenger corn- Also in is a switchhaving a temperature sensing element in the coolant line between the Iengine and the heater. In `this manner, the heater fan circuit can be maintained in an open condition so long as the coolant (hereinafter called turned to ground through control whereby. cool .air will be provided so long as the contacts are maintained closed. However, upon sensing of a ,passenger compartment temperature below a desired level, the temperature responsive yelement will open the normally-closed contacts and open the circuit through the cooling fan motor.V

The full nature of the invention will be understood from the accompanying drawings and the following de'- scription and claims:

vFIG. 1 is a schematic plan having a liquid cooled engine, heater, air-conditioner, and incorporating a typical embodiment of the present invention. v

viewY of an automobile FIG. 2 is a schematic diagramillustrating the principal electrical circuit features and control mechanism according to the typical embodiment of the invention FIG. `3 is -a front elevation of thecontrol `mechanism case or housing, illustrating the manual controls thereon.

FIG. 4 is an end view of the'control mechanism assembly with an end cover plate removed and illustrating Ycertain interior details. I

Referring to FIG. l, the .automobile body outline is designated by reference numeral 11 and the automobileA includes a -liquidjcooled engine 12 having water conduits 13 and 14 extending therefrom to the heater 16.V Typical- 1y theV conduits 13 and 14 are heater hose and conduit 13 suppliesV hot water from the engine to the heater core.

The hea-ter 16 is supplied with air for the passenger compartment 17 by means of a fan having an electric drive motor 18. The fan inlet 19 isprovided at some location on the body of the vehicle which is aerodynamically neutral such as at thel fender side ory fender top or at the cowl adjacent the side of the vehicle. c

manner, air flow through the fan andheater which might In this otherwise be caused -by ram effect at highervehicle speeds, is avoided. While a neutral inlet position is not mandatory, it does tend to facilitate control of vehicle temperatui-ey where changes ,in vehicle speeds are substantial, such as between city tra'c speeds and open highway speeds.

The air ow output of the heater is convyed through passageway 21 to the heater duct portion 22 havingpassenger compartment heating outlets 23 and 24, for exam- 27, for example. and defroster outlets are shown in the drawing than are usually provided in the vehicle. A damper 28 is pivotally mounted at 29 to the heater outlet ducting and is movable to a position 31fshown .by the dotted lines wherein theentire airflow output from the heater is directed to the defroster outlets.

An air-conditioning system is also provided and may typically include the evaporator unit 32,V a fan driven by c Van electric motor 33 with the vfan inlet 34 in a neutral conditioning compressor clutch 42, through conductor 5,4 to the air-conditioner fan motor 33 and by-pass valve 37and through conductor 56 to the heater fan motor 18. The clutch 42, air-conditioner fan motor 33, bypass valve 37, andthe heater fan motor 18 are all reunit 57 which will now be described.

Referring to FIGS. 2, 3 and 4, the control unit 57 includes a case having a generally rectangular form with a front face 58, top 59, bottom 61 and rear wall 62. It also has end cover plates 63 on each end. The cover plates as well as the rear wall`V and the bottom of the case are usually provided with a number of holes 64 to facilitate air circulation Vthrough the case.

A balance lever 66 is pivotally mounted to the case by means of the shaft 67 extending between the top and bottom 59 and 61 of the case respectively. `A bellows 68 has one end 69 thereof mounted to the inside of the front wall 58 of the case andy has a pointed projection 71 at the opposite end thereof engaging the seat 72 secured to the balance level-66. Thus, expansion of the bellows in response to increases of temperature of air flowing through the case is effective to move the balance lever clockwise as viewed from the top in FIG.l 2.

A snap-action switch 73, of the type manufactured by Micro-Switch Company, for example, is mounted to the case and has an operating button 74 extending inside the` i it is seen that rotation of thebalancel lever counterclock- Aple,'and .through passageway 26 to the defroster outlets For clarity of illustration, fewer heater wise is effective to move Aswitch button 74 to operate the switch 73. In theillust'rated example, the switch may be understood to have a common terminal 79, a terminal 81 connectedto the normally closed contactsV 82 of the switch, and a terminal 83 connected to the normally open contacts 84 of the switch.

- To establish means for conveniently manually adjustling the temperature at which switch 73 is actuated by the balance lever 66, an adjusting spring 86 isY connected at 87 to the balance lever and isconnected to the threadled nut 88 which is threadedly engaged with the threaded shaft 89 having an unthreaded portion 91 mounted for rotation in the front wall S8 of the case. A temperature setting knob 92 is secured to the outer end of the shaft 89 and is provided Vwitha pointer 93 whereby registry with a selected one of the temperature markings 94 on the front wall'58 can be `manually provided to obtain operation of switch 73 by bellows 68 at they selected temperature.

'A manually operable automatic-defrost lever 96 is vpivotally mounted to the case by means of the shaft 97.

Also, asv is'apparentin FIG. 4, anY arm 98 having the gen- -eral shape of an inverted L is pivotally mounted to the case by means of the shaft 97 andhas a pin 99 therein which is received 'in an aperture in the lever 96 whereby the arm 98 can be rotated with respect to its shaft axis ,97 by operating the`lever 96.. A knob 101 is provided at the frontend of the lever operation thereof.

Ofcourse, the case can take configurations other than that shown, so long'as asuitable frame is provided for support of the-various elements of the control unit.

As is apparent by comparing FIGS. 2 and 4, the arm 98, particularly the downwardly extendingportion 98a thereof, isin aposition to engage the 'offset portion 102 ofthe balance lever 66 upon movement of the manual n 96 to facilitate manual ,lever 96 to the'right-hand location thereof in the defrost notch 103 in the front wall 58 of the case. The spring 104 shown in FIG. 4 serves to pull the lever 96 up into the notch 103 upon positioning of the lever inthe righthand extreme of the slot 106. By thus engaging the olfset portion 102 of the balance-lever 66, the screw 76 is forceably engaged with the operating button of the switch 73 regardless of the condition of the bellows 68.

In contrast, with the lever 96 engaged in the auto- Vmatic notch 107 of the front panel 58 of the case, it is the bellows operation which controlsthe operation of the switch button 74.

At ythe rear end .108 -of the manualv lever 96, there are V.provided apertures 109 intended to receive the pin 111 of the defroster damper cable yclamp 112 which is secured thereto by a suitable spring clip 113. The clamp 112`s"V The other end of the cable 116 is secured to the outlet ductfrom the heater 16 of FIG., 1 andthe other end of the wire is secured to the damper *28. Accordingly, movement of the manually operated lever 96 to the defrost notch 103 not only causes a positive and4 preferential operation of the switch 73 but also closes the damper 28 whereby the entire heater..air output is directed to the defroster outlets 27.

Referring further to FIG. 2, the electrical circuit employed according to the present invention can be readily understood. For the contr-ol of the vehicle heater, a lirst circuit may .be described .as the series connection of the vehicle battery 51, a master switch .121 which may be the ignition switch of the vehicle forexample, the heater fan motor 18, the normally open contacts 84of the switch 73, the commonconductor 122:, the normally openconftacts of the thermally responsive switch 123 and back to the battery through ground. Y j

.The switch 1123is normally open until the tempera-ture sensing unit thereof 124 rises to a predetermined temperature whereupon the switch closes. This switch is mounted in a brass casing 126 which may be inserted in-wa=ter line 13, forexample, .by connecting each end of a heater hose to one end of the brass unit by means of hose clamps 127. The annular ridgesr128 in the brass ttingassure Va tight tit of the heater hose to the fitting by applying hose clamps to thev hose'at points which are between the ridges 128.

A second circuit, which may be described as the cooling system control circuit, includes l the vehicle battery 51, Ina-ster switch 121, the air-conditioning fan motor 33, the normally closed contacts 82 of switch v73, the conductor 122, switch 123 and back through ground to lthe battery. Another circuit likeA the foregoing circuit-.is provided and includes the air-conditioning compressor clutch 42. Additional identical circuits including othery electricall` elements of the cooling system, such as valve 37 of FIG. .-1 for example, may also be provided;

It may bevob'served `at this point that? by virtue of the provision ofthe switch'123 in the groundreturn frorithe heater andan-conditioner electrical units, neither of Vthe units can be energized until .the water temperature from the yvehicle engin'e'has risen .to an acceptable level to assure that when the heater fanisrloperatedjthe: air circu-l lated thereby will be warm. It will be recognized, however, that if desired, the common terminal 79 of the switch 73 can be returned directly to ground. In this instance, operation of the vehicle air-conditioner `could begin immediately in the event the passenger compartment temperature were at a level which would demand a cooling function. In this instance, if it were desired to prevent the heater from blowing cold air in the system when .the heating function was desired, the switch 123 could be connected in series in the line 131 between the heater fan motor 118 and the normally open contact terminal 83 of switch 7-3.

From the foregoing description, it can be recognized that with the manually -operated lever in the automatic notch and ,with the temperature adjustment knob set for the desired passenger compartment temperature, completely automatic temperature control is provided according to the present invention. In a vehicle equipped with Ian `air cooling system `as well as a heater, a desired temperature can be provided regardless of the external ambient temperature conditions.

By virtue of .the complete automatic feature of the present invention, we remedy the safety hazard .presented by the temperature control systems heretofore available, which necessitated continuously looking for and adjust- The , 6 ing temperature. Where the 4switch 73 is the'type which simultaneously closes and opens the normally open and normally closed contacts respectively, andis employedin a `vehicle having .a cooling-system as well as a heating sysf tern, a continuous ilow of .air can be provided. 0n the other hand, if desired, theswitch 73-can Ibe such as t0 provide a delay between the opening and the closing functions or require a measure of` additional travel of the opera-ting member to close the second set of contacts in which case the transition from the heating toa cooling function would not be immediate. This may be found desirable where continuous yair-flow i-s not required and a slightly less precise temperature can be tolerated.

A preset, therm-ostatically operated, immersion switch :123 prevents the waste'of using the heater andalso-the cold air-conditioning in .a car before the water has warmed enough .to provide a flow of warm air from the heater. 'Ilhe unit eliminates the need for a two-speedmotor on the heater fan and also eliminates separate temperature and.

defroster controls thus providing a cost benefit and faciliication of control whereby the vehicle occupant neednot guess at the correct position for a desired passenger cornpartment temperature. T-he elimination of any watercontrol valve `or the necessity therefor, eliminates a common source of trouble present in conventionalheating systems.

It can ythus be .appreciated` from the foregoing description'that allof the objects recited above plus other objects not yspecically mentioned. are achieved by the present invention .and many benets can -be derived therefromV particularly from the standpoints of durability, simplicity of installation, economy of construction and installation, versatility, facility of operation and accuracy of temperature control.

While the invention has been disclosed andI described insome detail in the drawings and foregoing description, they are to be considered asillustrative and not restrictive in character, asother modifications may readily, suggest themselves to persons skilled in thisart and within the broad scope of the` invention, reference being had to the appendedV claims.

The invention claimed is:

1. In a vehicle having a compartment, a1 motor heating a fluid, andan air heater` heatedby'saiduidwith a fluid conduit connected between said heater andmotor to convey said fluid in a fluid path throughsaidmotor and heater, andl having an electric fan motor and fan `for moving air through saidheater and into the compartment,

a compartment temperature control circuit comprising:

'said fan motor;

a` source of electrical energy coupledto said fanmotor;

and a rst temperature responsive electrical switch means coupled to said source and to said fan motor to complete the circuit, said first switch means being located in said compartment remote from said heater to respond to compartment temperatures to open the circuit at compartment temperatures above a predetermined level;

and second temperature responsive electrical switch means in series with said irst switch means and located to respond to temperature of said iiuid in said conduit to open said circuit at a fluid temperature below a predetermined level.

2. In a vehicle having a compartment, a motor heating a fluid, an air heater heated by said iiuid with a uid conduit connected between said heater and motor to convey said fluid in a uid path through said motor and heater, and having an electric heater fan motor and fan for moving air through said heater and into the compartment, and having an air cooling system with a cooling fan and cooling fan motor, a compartment temperature control system comprising:

a source of electrical energy coupled to said fan rno cooling fan motor, and said normally-closed contacts in series.

3. In a vehicle having a compartment, a motor heating a uid, an air heater heated by said fluid, with a fluid conduit connected between said heater and motor to convey said fluid in a fluid path through said motor and heater, and having an electric heater fan motor and fan for moving air through said heater and into the compartment, and having an air cooling system electrically operable to supply cool air to the compartment, a control system comprising:

a source of electrical energy coupled to said fan motor and said air cooling system; and

and a iirst electrical switch having an operator operating normally-open and normally-closed switch contacts at temperatures below a predetermined level' and to close said normally-open contacts at temperatures below a predetermined level; a heater fan circuit including said'source, said heater fan motor, and said normally-open contacts in series;

and an air cooling system including an air conditioner fan and motor therefor, a cool air outlet, an evaporator between said air conditioner fan and said cool air outlet, and a cooling system circuit, said circuit including said source, said air conditioner fan motor and said normally-closed contacts in series,

to energize said cooling system for supplying cool air to the compartment during'closure of said normally-closed contacts.

4. In a vehicle having a passenger compartment with a window, a motor heating a liuid, and an air heater heated by said uid, with a uid conduit connected between said heater and motor. to convey said fluid in a uid path through said motor and heater, and the vehicle having a iirst outlet disposed'principally for heating purposes and aY second outlet disposed principally for window defrosting purposes, and a passageway coupling said heater to said outlets and a damper in saidpassageway to selectively decouple said first outlet from said heater, and the vehicle having'a fan and an electric fan drive motor for moving air through said heater, said passageway and said outlets, a passenger compartment temperature controller comprising:

a frame;

a switch having normally-open contacts and an operating member; v

a circuit including in series relation a source of electrical energy, the said fan drive motor, and said normally-open contacts;

a thermally responsive unit mounted to said frame and having a portion operatively associated with said switch Aoperating member and having a portion subject to passenger compartment air temperature to close said contacts in response to temperatures below a predetermined level;

and a manually operable element operatively associated with said switch operating member to close said contacts in a predetermined manually selectable position of said element, independent of the air temperature; v

and means coupling said element to said vdamper to decouple said first outlet from said heater when said element is in said predetermined position.

5. A controller as set forth in claim 4 further comprising:

a thermally responsive switch having contacts in said circuit and having a portion communicating with said fluid to close the contacts of said thermally responsive switch in response to fluid temperatures above a predetermined level.

v References Cited by the Examiner UNITED STATES PATENTS 1,703,235 2/29 Heath.

2,024,385 12/35 Persons 165-26 2,446,677 8/48 Vaughan et al. ,2,450,478 10/48 Johnson 16S- 26 2,583,661 1/52 Morrison 20G-140 X 2,656,114. l10/53 Woods.

2,735,657 2/56 Owen 165-43 2,870,296 1/59 Heal 200-140 2,953,356 9/ 60 Soule.

3,103,568 9/ 63 Lieberman et a1. 200-140 5' CHARLES sUKANLo, Primm Examiner. 

1. IN A VEHICLE HAVING A COMPARTMENT, A MOTOR HEATING A FLUID, AND AN AIR HEATER HEATED BY SAID FLUID WITH A FLUID CONDUIT CONNECTED BETWEEN SAID HEATER AND MOTOR TO CONVEY SAID FLUID IN A FLUID PATH THROUGH SAID MOTOR AND HEATER, AND HAVING AN ELECTRIC FAN MOTOR AND FAN FOR MOVING AIR THROUGH SAID HEATER AND INTO THE COMPARTMENT, A COMPARTMENT TEMPERATURE CONTROL CIRCUIT COMPRISING: SAID FAN MOTOR; A SOURCE OF ELECTRICAL ENERGY COUPLED TO SAID FAN MOTOR; AND A FIRST TEMPERATURE RESPONSIVE ELECTRICAL SWITCH MEANS COUPLED TO SAID SOURCE AND TO SAID FAN MOTOR TO COMPLETE TO CIRCUIT, SAID FIRST SWITCH MEANS BEING 